Objective: The purpose of the present study was to examine the experimental and epidemiologic evidence linking benzodiazepine use to driving impairment.

Data Sources: We searched MEDLINE, PsycINFO, the Cochrane Collaboration, and EMBASE using the key terms ("benzodiazepines" OR "exp benzodiazepines") AND
("automobile driving" OR "accidents, traffic" OR "driving" OR "driver$") and limited the results to English citations from 1966 to August 5, 2005, with auto-updates for MEDLINE and PsycINFO to November 30, 2007.

Study Selection and Data Extraction: Experimental studies using driving simulators and
on-road tests were sought, as were epidemiologic studies of a case-control or cohort design. Data were extracted by blinded raters and pooled using random-effects models. We excluded studies without control groups or without measures of driving or collisions. Studies with driving measures that could not be combined were also excluded.

Data Synthesis: Of 405 potential articles, 11 epidemiologic and 16 experimental studies were included in the meta-analysis. Associations between motor vehicle collisions (MVCs) and benzodiazepine use were found among 6 case-control studies (OR = 1.61, 95% CI = 1.21 to 2.13, p

Conclusion: Benzodiazepine users were found to be at a significantly increased risk of MVCs compared to nonusers, and these differences may be accounted for by a difficulty in maintaining road position.